Cinematograph apparatus



. Feb. 4, 1936.

A. l?. JoHNsoN CINEMATOGRAPH APPARATUS 2 Sheets-Sheetl 1 Filfed Nov. 8,1934 Feb. 4, 1936.

A. P. JOHNSON CINEMATOGRAPH APPARATUS FiledI Nov. 8.' 1934 2Sheets-Sheet 2 Y mow Y- .n AH A posed a cylindrical passage II PatentedFeb. 4, 1936 2,029,871 Y CINEMATOGRAPH APPARATUS Arthur Percy Johnson,Wylde Green, Birmingham, England Application November 8, 1934, serialNo. 751,978

In Great Britain November 11, 1933 13 Claims.

y This invention relates to cinematograph -apparatus including a chambercontaining liquid adapted to be disposed between the projection lightand the lm, means being provided for heating the liquid to maintain itat a temperature suiicient to eliminate condensation upon thetransparent sides of the chamber.

The object of the present invention is to provide an improved ormodified construction of such apparatus which will provide improvedcool' ing of the projection beam and will minimize or prevent thepossibility of by exposure to the heating eiect of the projection beam.

Refi .'ring to the drawings:-

Figure 1 is a perspective View of one form of apparatus constructedaccording to the present invention.

Figure 2 is a sectional side elevation of same.

Figure 3 is a a plan view of same.

Figure 4 is a sectional end elevation of same with a slight modificationapplied.

In the construction illustrated in the accompanying drawings, the mainstructure of the unit comprises a single casting formed at its upperpart into an open ended tank I0, beneath which is diswhich extendsthrough the casting from side to side.

Within the passage is mounted a liquid chamber comprising-a cylindricalsleeve I2 formed at each end with an integral shoulder I3 against whicha transparent glass window I4 is clamped by means of a screwed ring I5,packing washers I6 being provided in each aide of each glass to form aliquid tight joint. I

A lter or screen is mounted in the chamber:y

between the Windows I4, this filter or screen comprising two glasses YIIclamped between sleeves I8 inserted within the chamber I2 and clamped inposition by the rings I5.

The windows I4 are formed from heat resisting glass and may, be tinted,for example green. The glasses I1 may also `be coloured and one may beof green glass and the other of pink glass.

'I'he tank I0 is adapted to form a reserve tank for cooling liquid withwhich the chamber I2 is to be lled and communicating passages areprovided between the tank and the chamber.

A vertical passage I9 is formed through the casting from the base of thetank I 0, this passage communicating with a horizontal passage extendinginto a further short vertical passage 2l disposed beneath the chamber I2as shown in Figure fl.

The passage 2I is screw-threaded at its lower the film being damaged.

end and a union nipple 22 is screwed into this passage to close thelower end thereof.

This nipple is formed with a tubular shank 23 at its upper end and aportion 24 of reduced diameter extends through a hole in the lower sideof 5 the chamber I2.

Radial holes 25 are formed in the shank 23 to complete the communicationbetween .the passage 20 and the interior of the chamber I2 and a liquidtight joint is providedy between the nipple and 10 the chamber bycmeansof a packing washer 26 disposed around the reduced end 24.

The casting is' formed with an integral hollow boss 21 which projectsupwardly from the base of the tank I0 and in this boss is disposed afurther 15 nipple 28 which screws into a screw-thread in the upperportion of the bore through the boss 21.

The nipple 28 is similar to the nipple 22 previously described and areduced end 24 extends through a hole in the chamber I2, the joint being20 sealed by a ring 26, but a passage extends entirely through thenipple 28 so that the liquid can flow from the upper part of the chamberI2 into the A reserve tank I0.

'Ihe cooling liquid can thus circulate between 25 the tank I0 and thechamber I2 and as heated liquid passes from the top of the chamberthrough the nipple 28, cool liquid Uflows from the tank I0 through thepassages I9 and 20 and enters the lower part of the chamber I2 throughthe nip- 30 ple 22.

The glasses II are disposed in alignment with the nipples 22 and 2a sothat the coming liquid is directed over both sides of the filter orscreen and the possibility of unequal heating of the two faces 35 is miimized. The glasses II are recessed or cut aw at points opposite to thepositions of the nipples, asfshown at 29 in Figure 4, so that the liquidcan flow readily between the chamber and the nipples.

In order to raise the temperature of the liquid initially and tomaintain a temperature sufficient to eliminate condensation on thetransparent sides of the chamber I2, an immersion heater 30 is mountedin the reserve tank and is located in position by a spring clip 3|engaging over the upper edge of the tank.

To one side of the casting is attached a flange 32 by means of which theapparatus may be secured to the lamp house and whilst this flange isformed with a central aperture to allow the light to pass through thetransparent sides I4, the opening is of lessarea than that of thesection of the passage II, so that the ange overlaps the end of thispassageand forms a stop shoulder.

To the opposite side of the casting is attached a conical or converginghood 33 provided with an attachment flange and spigot 3d which entersthe end of the passage I I as shown in Figure 2, whilst at itsprojecting end the hood is formed with an aperture or gate 35 acrosswhich the film, as shown at 36, is paed when the apparatus is in use.

To the underside of the hood is secured an air conduit or duct 3l, andan air blast from a suitable blower or the like is directed along thisconduit or duct into the hood and through the gate or aperture 35 on tothe surface of the iilm.

A side window 38 is provided in the side of the hood to enable theoperator to focus the light on tothe film being projected and a red orother suitably coloured glass may be provided in this window.

In the top of the hood louvres or exhaust holes 39 are provided so thatthe air can escape from the hood and to avoid trapping of warm air inthe upper portion of the hood.

A branch pipe fill extends from the conduit 3l around the side of thefilm and this pipe is perforated so that cooling air can be directed onto the front face of the film being projected.

In order to prevent or minimize possible damage to the projectionapparatus due to leakage of the liquid by fracture of one of the glassesIt, a valve II is mounted in the lower end of the passage I9 so that theliquid can readily be drained away.

rIhis valve is provided with an apertured closure slide l2 and if one ofthe glasses Ifl cracks or it is desired to empty the chamber I2 for anyother reason, the cooling liquid can be drained into a suitablecontainer by moving the closure slide cl2 into the open position.

With this construction the light from the projection lamp passes throughthe liquid cell comprising the glasses Ill, the glasses Il, and thecooling liquid in the chamber I2 and the combined effect of this cellremoves from the projection beam the heat rays which would be liable todamage the lm.

With projection apparatus working at higher temperatures in order toobtain increased light intensity in the beam, there is a considerableamount of heat in the beam particularly when the beam is produced by anarc between metal coated electrodes and unless this heat is removedthere is considerable danger of the lm being damaged. In addition, undercertain circumstances the feed of film through the apparatus is stoppedand unless the beam is interrupted or a gate inserted in front of thefilm, a single portion of the film is exposed continuously to theprojection beam for a period dependent upon the time of stoppage.

If exposed to the full heat of the beam there would be greater danger ofthis small piece of iilm being permanently damaged or even heated toring point, in which case the whole film and possibly the apparatusitself would be endangered.

The cooling cell above described removes this dangerous heat before thelight reaches the iilm which can thus be exposed continuously withoutdanger for sufficient time to allow the cause of the stoppage to beremoved or corrected.

In addition the cooling air blast directed on to both sides or faces ofthe film further reduces the danger of over-heating of the part exposedto the projection beam so that the possibility o.'

fire due to over-heating of the nlm is eliminated or substantiallyreduced.

In addition air is directed o'n the adjacent portions of the apparatuswhich are exposed to the heating effects of the beam such for example asthe projector back plate across which the lm passes in use. Such partsare consequently cooled and distortion due to over-heating is reduced oreliminated with a consequent increase in the life and eiiiciency ofoperation of the apparatus.

As the liquid in the chamber I2 becomes heated by the projection beam athermal siphon circulation is set up between the chamber and the reservetank, heated liquid flowing from the top of the chamber up the nipple 28and further liquid owing from the tank into the lower part of thechamber through the passages I9 and 2i) and the nipple 22.

Where it is desired to remove the chamber I2, either the flange 32 orthe hood 33 is detached from the casting and when the unit is secured tothe back of the lamp house by means of the flange 32, it is preferableto remove the hood 33.

The nipples 22 and 28 are then screwed out until the ends 24 arewithdrawn from the openings in the chamber, after which the latter canbe slidden out of the passage II.

In the construction described, it would, of course, be necessary todrain the liquid both from the chamber and from the tank IB but with themodification illustrated in Figure 4, draining of the tank Ill isavoided, valves being provided to cut oi the communication between thetank ID and the chamber I2, and it isonly necessary to drain the latterand the reserve of liquid may be retained in the tank I0.

A valve (i3 is provided at the upper end of the nipple 2B with a furthervalve 43 at the upper end of the passage I9, each valve being mounted ona valve rod 44 guided in a bracket 45 on the interior of the tank I0.The two rods M are coupled by a link 46 which is connected by a furtherlink dll to one end o'f an operating lever i8 pivoted between brackets49 at the top edge of the tank Ill.

To the projecting endof the lever 48 is pivoted a spring pressed catch50 adapted to engage a lug 5I on the bracket 49 to retain the valves 43in the open position against the action of the spring 52. Y

In normal use the apparatus is in the position shown in Figure 4 so thatcommunication is established between the tank IIJ and the chamber I2 butthis communication can be cut off by releasing the catch 50 and allowingthe valves 43 to clo'se under the eiect of the spring 52.

Thus, in the event of fracture of the glasses Ill, the liquid inthe tankII) can be shut off from communication with the chamber I2, which lattercan be drained of liquid by means of the valve III and the chamber I2can readily be reiilled for use when the failure has been repaired.

1. A cooling unit for use with cinematograph apparatus including a bodyhaving in its upper part a reserve tank and in its lower part a chammber, a transparent panel in each of two opposite sides of said chamber,liquid circulating passages between said tank and said chamber, coolingliquid in said tank and said chamber, said cham- H ber being adapted tobe arranged with said transparent panels interposed in the light beamfor projecting a iilm, a hood attached to said body at one side of saidchamber, an air supply con i duit communicating with said hood, andmeans located in 4said tank for heating the liquid to a temperaturesuilicient to eliminate condensation on the transparent panels of saidchamber.

2. A cooling unit for use with cinematograph projection apparatusincluding a body having in its upper part a reserve tank and in itslower part a chamber, a transparent panel in each of two' opposite sidesof said chamber, cooling liquid in said tank and said chamber', liquidcirculating passages between said tank and said chamber, a hood attachedto said body at one side of said chamber, said hood having an opening inits projecting end, an air supplyconduit communicating with said hoodfor directing air on `one face of a film passing said opening, a furtherair supply conduit for directing air on the other face of said lm and aheating element in said tank for heating the liquid to a temperaturesufcient to eliminate condensation o'n the transparent panels of saidchamber.

3. A cooling unit for use in cinematograph apparatus including a bodyhaving in its upper lpart a reserve tank and in its lower part an openended passage, a cylindrical chamber in said passage, a transparentpanel at each en d of said chamber, liquid circulating passages betweensaid tank and said chamber, cooling liquid in said tank and saidchamber, said chamber being adapted to be arranged with said transparentpanels interposed in the light beam for projecting a film, a transparentscreen in said chamber between said transparent panels and an air supplyconduit-at one side of said chamber.

4. A cooling unit for use in cinematograph apparatus including a bodyhaving in its upper part a reserve tank and in its lo'wer part an openended passage, a cylindricalchamber in said passage, a transparent panelat each end of said chamber, a heat screen in said chamber between saidtransparent panels, said screen comprising a pair of glass platesmounted face to face, cooling liquid in said tank and said chamber,liquid circulating passages between said tank and said chamber, saidpassages communicating with said chamber at the position at which saidheat screen is mounted `so that liquid is circulated' over both faces ofsaid screen, said chamber being adapted to be arranged with saidtransparent panels interposed in the light beam for projecting a filmand an air supply conduit at one side of said chamber.

5. A cooling unit for use in cinematograph apparatus including a bodyhaving in its upper part a reserve tank and in its lower partan openended passage, a cylindrical chamber in said passage, a transparentpanel at each end of said chamber,a heat screen in said chamber betweensaid transparent panels, said screen comprising a pair of glass platesmounted face to face, cooling liquid in said tank and said chamber, atubular nipple in said body communicating with the lower part of saidchamber, liquid circulating passages in said body connecting said nippleto said tank, a further tubularnipple in said body connecting the upperpart of said chamber to said tank, said nipples communicating with saidchamber at the position at which said plates are mounted so that liquidis circulated over both faces of said plates, said chamber being adaptedto be arranged with said transparent panels interposed in ,the lightbeam for projecting a film and an air supply conduit at one side of saidchamber.

6. A cooling unit for use in' cinematograph apparatus including a bodyhaving in its upper part va further tubular nipple in said bodyconnecting the upper part' of said chamber to said tank, said nipplescommunicating with said chamber at the position at which said plates aremounted so that liquid is circulated over both faces of said plates, ahood attached to said body at one side vof said chamber, said hoodhaving an opening in its projecting end, said opening forming a gateacross which a lm to be projected is adapted to be moved, an air supplyconduit communicating with said hood anda further air supply conduitdisposed externally of said hood near said opening, so that air can bedirected on both faces of a film passed between said further air conduitand said opening.

7. A cooling unit for use with cinematograph projection apparatusincluding a body having in its upper part a reserve tank and in itslower part a chamber, a transparent panel in each of two opposite sidesof said chamber, said chamber being adapted to be arranged with saidtransparent panels interposed in the projection beam plates of heatresisting glass mounted face to face in said chamber between saidtransparent panels, cooling liquid in said tank and said chamber, saidbody having a passage connecting the lower part of said chamber to saidtank, and a further passage connecting the upper part of said chamber tosaid tank, said passages communicatingA with said chamber atthe-position occupied by said transparent plates so that liquid iscirculated l over both faces of said condenser, valve means for cuttingoff the ow through said passages, a hood attached to said body at oneside of said chamber, said hood having an opening in its projecting end,said opening forming a gate across which a lilm to be projected isadapted to be moved, an air supply conduit communicating with said hoodfor directing air on said gate, and a heating element in said tank forheating the liquid to a temperature suicient to eliminate condensationon the transparent panels of said chamber.

8. A cooling unit for use with cinematograph `projection apparatusincluding a body having a reserve tank, a chamber, a transparent panelin each of two opposite sides of said chamber, said chamber beingadapted to be arranged with said transparent panels interposed in theprojection beam, a heat screen in said chamber between said transparentpanels, said screen comprising a pair of glass plates mounted face toface, cooling liquid in said tank and said chamber, said body having apassage connecting the lower part of said chamber to said tank, afurther passage connecting the upper part of said chamber to said tank,valve means for cutting off the flow through said passages, a valve fordraining the liquid from said chamber, a hood attached to said body atone side of said chamber, said hood having an opening in its projectingend, said opening forming a gate across which a lm to be projected isadapted to be moved and through which the light beam is directed, an airsupply conduit communieating with said hood, a. further air supplyconduit disposed externally of said hood near said opening, so that aircan be directed on both faces of a film passed between said further airconduit and said opening and an immersion heating element in said tankfor heating the liquid to a temperature suicient to eliminatecondensation on the transparent panels of said chamber.

9. A cooling unit for use with cinematograph projection apparatusincluding a body having in its upper part a reserve tank and in itslower part an open ended passage, a cylindrical chamber in said passage,a transparent panel at each end of said chamber, a heat screen in saidchamber between said transparent panels, said screen comprising aplurality of plates of tinted glass, cooling liquid in said tank andsaid chamber, said body having a passage connecting the lower part ofsaid chamber to said tank, a further passage connecting theA upper partof said chamber to said tank, said passages communicating with saidchamber at the position occupied by said screen so that liquid iscirculated over both faces of said plates, valve means for cutting offthe ow through said passages, a valve for draining the liquid from saidchamber, said chamber being adapted to be arranged with said transparentpanels interposed in the projection beam, a hood attached to said bodyat one side of said chamber, said hood having an opening in itsprojecting end, said opening forming a gate across which a lm to beprojected is adapted to be moved and through which the light beam isdirected, an air supply conduit communicating with said hood, and afurther air supply conduit disposed externallyof said hood and adaptedto direct air on the opposite face of the film to that exposed at saidopening.

10. cinematograph projection apparatus including a body having in itsupper part a reserve tank and in its lower part a chamber, coolingliquid in said tank and said chamber, a transparent panel in each of twoopposite sides of said chamber, said chamber being disposed with saidtransparent panels interposed in the light beam for projecting a lm,transparent glasses arj ranged face to face in said chamber between saidtransparent panels, means for clamping said glasses in position in saidchamber, said chamber having in its wall an upper and a lower opening atthe position at which said glasses are clamped, tubular nipples in saidbody projecting one into each of said openings in` the chamber, sealingmeans between said nipples and said chamber and liquid passagesconnecting said nipples to said tank.

11. Cinematograph projection apparatus including a body having in itsupper part a reserve tank and in its lower part an open ended passage, acylindrical chamber in said passage, cooling liquid in said tank andsaid chamber, a transparent panel at each end of said chamber, saidchamber being disposed with said transparent panels interposed in thelight beam for projecting a lm, a pair of glass discs arranged face toface in said chamber between said transparent panels, clamping sleevesin said chamber securing said discs in position, said chamber having inits wall an upper and a lower opening at the position at which saidglasses are clamped, a tubular nipple in said body, said nipple openinginto said tank and projecting into the upper opening in said chamber, alower nipple in said body projecting into the lower opening in saidchamber,

said body having liquid passages connecting said lower nipple with saidtank, and sealing means between said nipples and said chamber.

12. A cooling unit for use with cinematograph apparatus including a bodyhaving in its upper part a reserve tank and in its lower part a chamber,cooling liquid in said tank and said chamber, a transparent panel ineach of two opposite sides of said chamber, said chamber being adaptedto be arranged with said transparent panels interposed in the light beamfor projecting a lm, transparent glasses arranged face to face in saidchamber between said transparent panels, means for clamping said glassesin position in said chamber, said chamber having in its Wall an upperand a lower opening at the position at which said glasses are clamped,tubular nipples in said body projecting one into each of said openingsin the chamber, sealing means between said nipples and said chamber andliquid passages connecting said nipples to said tank.

13. A cooling unit for use with cinematograph projection apparatusincluding a body having in its upper part a reserve tank and in itslower part an open ended passage, a cylindrical chamber in said passage,cooling liquid in said tank and said chamber, a transparent panel ateach end of said chamber, said chamber being adapted to be arranged withsaid transparent panels interposed in the light beam for projecting alm, a pair of glass discs arranged face to face in said chamber betweensaid transparent panels, clamping sleeves in said chamber securing saiddiscs in position, said chamber having in its wall an upper and a loweropening at the position at which said glasses are clamped, a tubularnipple in said body, said nipple opening into said tank and projectinginto the upper opening in said chamber, a lower nipple in said bodyprojecting into the lower opening in said chamber, said body havingliquid passages connecting said lower nipple with said tank, and sealingmeans between said nipples and said chamber.

ARTHUR PERCY JOHNSON.

